authentication problem Google Nexus 7

I have a Google Nexus 7 which I have added to my homehub 3 back in December. All good, has been connecting everyday with no problems until yesterday when I got 'Authentication problem' appear and it switches to use BTFON or BT Open Zone. I have tried rebooting the router, forgetting the network on the Nexus and then rejoining it but neither has worked. Please help. Hoping you can help. Thanks in advance.

Re: authentication problem Google Nexus 7

Try this: Go to Settings >Wifi and click on your network. Click to forget it. Rescan and click on your network. Enter your information as you normally would, but click advanced before confirming and go down to IP Address. Change from DHCP to Static. Go to IP Address and change it to something like 192.168.1.77 for example. Just confirm and hopefully its rectified.